Diallyl disulfide induces apoptosis and autophagy via mTOR pathway in myeloid leukemic cell line

Leukemia is a hematological malignancy which is produced by uncontrolled proliferation of leukocyte precursors. Currently, alternative medicines, using herb extracts, have been developed for cancer treatment. In this study, the effect of diallyl disulfide (DADS) on the induction of apoptosis and autophagy was investigated in K562 and NB4 myeloid leukemia cells. Leukemia cells were treated with various concentrations of DADS for 24 and 48 h. The percentage of cell viability was measured using an MTT assay. The percentages of apoptosis and autophagy were analyzed by staining with annexin-FITC and anti-LC3 FITC-conjugated antibodies, respectively. Then, the stained cells were detected by flow cytometry. In addition, PP242, a mammalian target rapamycin (mTOR) inhibitor, was used to study the involvement of the mTOR pathway in DADS-induced apoptosis and autophagy. mTOR mRNA expression was measured by real-time PCR. The results showed that DADS decreased cell viability and increased the percentage of cell apoptosis in a dose- and time-dependent manner. mTOR expression was significantly decreased in DADS- and mTOR inhibitor-treated cells. The highest percentages of apoptosis and autophagy were shown in cells treated with 100 mu g/ml DADS combined with 10 mu M of the mTOR inhibitor. According to our results, DADS could induce apoptosis and autophagy via the mTOR pathway in both K562 and NB4 myeloid leukemia cell lines.